To know the germicidal efficacy of a binary liquid Chlorine Dioxide Disinfectant(stablilized Chlorine Dioxide liquid).Method Carrier quantitative germicidal test was used to study its efficacy in killing Escherichia coli with different chlorine dioxide concentration and different contact time.Results The D value of efficacy of the solution containing chlorine dioxide 100 mg/L in killing E.coli was 1.37 min,and the concentration coefficient was 0.6582.The solution containing chlorine dioxide 100 mg/L with a 6 min contact time killed 100% of E.coli on carriers.Conclusion The binary Liquid Chlorine DioxideDisinfectant has good efficacy in killing E.Coli.